Delphi ActiveX

Connect to an SSH Server Through Another (Jump Host)

Demonstrates the Chilkat Ssh.ConnectThroughSsh method, which connects to a second SSH server through an already connected and authenticated Ssh object. The first argument is the first (jump-host) Ssh object, and the second and third are the destination hostname and port.

Background: This is SSH chaining through a "jump host" (bastion): the application connects to a reachable gateway, then tunnels onward to a target that is only accessible from inside the network. Each hop is authenticated separately with its own credentials. The result is a normal Ssh object for the target that happens to be routed through the first connection.

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var
success: Integer;
sshJump: TChilkatSsh;
sshPort: Integer;
password: WideString;
sshTarget: TChilkatSsh;

begin
success := 0;

//  Demonstrates the Ssh.ConnectThroughSsh method, which connects to a second SSH server through
//  an already connected and authenticated Ssh object (a jump host).  The 1st argument is the
//  first Ssh object, and the 2nd and 3rd are the destination hostname and port.

sshJump := TChilkatSsh.Create(Self);

//  Connect and authenticate to the first SSH server (the jump host).
sshPort := 22;
success := sshJump.Connect('jump.example.com',sshPort);
if (success = 0) then
  begin
    Memo1.Lines.Add(sshJump.LastErrorText);
    Exit;
  end;

//  Normally you would not hard-code the password in source.  You should instead obtain it
//  from an interactive prompt, environment variable, or a secrets vault.
password := 'mySshPassword';

success := sshJump.AuthenticatePw('jumpUser',password);
if (success = 0) then
  begin
    Memo1.Lines.Add(sshJump.LastErrorText);
    Exit;
  end;

//  Connect to the target SSH server through the jump host.
sshTarget := TChilkatSsh.Create(Self);
success := sshTarget.ConnectThroughSsh(sshJump.ControlInterface,'target.example.com',sshPort);
if (success = 0) then
  begin
    Memo1.Lines.Add(sshTarget.LastErrorText);
    Exit;
  end;

//  Authenticate to the target server (separate credentials).
success := sshTarget.AuthenticatePw('targetUser',password);
if (success = 0) then
  begin
    Memo1.Lines.Add(sshTarget.LastErrorText);
    Exit;
  end;
Memo1.Lines.Add('Connected to the target through the jump host.');

sshTarget.Disconnect();
sshJump.Disconnect();